Prior art, including patents and publications known to applicant and his attorneys is quite remote from the construction of my improved device with the exception of my prior U.S. Pat. No. 2,820,291. The structure of my prior patent provides a pair of elongate sheath and handle plates hinged along corresponding ends to hinge means provided at the butt of the knife or other analogous tool. The hinge plates could be swung rearwardly away from the butt end of the knife blade into opposed relation with the free ends thereof in close relation to, in combination, constitute a handle. However, a detachable cap-retaining member was required which could be readily lost unless connected by a chain with one of the plate members. This retainer, in the form of a cap however, could not prevent lateral shifting and some endwise displacement of the two sheath members. A further requirement of my said patented structure was a T-shaped pin oscillatable in the closed end of the cap member for inter-engagement with means on the sheath to positively connect the cap. The patented structure was feasible and was put in commercial use, but has definite disadvantages. Some difficulty was always involved in properly oscillating the T-head member for connection with the ends of the two sheath members. The cap member itself was sometimes hard to slide in place and was easily lost.
It is a main object of my present invention to overcome the foregoing disadvantages and provide a very inexpensive combination of elements which positively rigidifies the two hinged handle and sheath plates to prevent longitudinal or lateral shifting of the same when the plates are positioned to constitute a handle for the knife blade or other tool.
A further object is the provision of an improved structure which may be manufactured at very low cost and without expensive jigs, tooling and other capital expense for commercial manufacture.
Still a further object is the provision in one form of the device of a saddle element which may be detachably secured to conventional knife blades readily purchasable on the open market, and which provides positive retaining means for the saddle to the butt end of the knife, together with the two essential hinge elements for connection with the swingable sheath plates or bars.